Merck, which sold $502 million of its Victrelis hepatitis C
drug last year, contacted Gilead this month requesting it
license two patents Merck says are related to sofosbuvir,
Gilead’s attorneys said a complaint filed yesterday in federal
court in San Francisco.

Merck, based in Whitehouse Station, New Jersey, asked
Gilead to pay a 10 percent royalty on the net sales of the
medicine until the patents expire, a request “meant to threaten
Gilead” on the eve of U.S. regulatory approval of sofosbuvir,
according to the complaint. Gilead seeks a judge’s declarations
that the patents aren’t enforceable or infringed so it won’t
have to license them to sell the medicine.

Gilead, based in Foster City California, said June 7 that
sofosbuvir will receive a priority marketing review by U.S.
regulators with a target review date of Dec. 8.

Hepatitis C attacks the liver and can lead to liver cancer.
The virus affects about 150 million people worldwide and the
market for new pills such as sofosbuvir is estimated at $20
billion.

Lainie Keller, a Merck spokeswoman, didn’t immediately
respond to an e-mail yesterday after regular business hours
seeking comment on the lawsuit.

The case is Gilead Sciences v. Merck, 13-04057, U.S.
District Court, Northern District of California (San Francisco).